This only holds if you start with the a priori assumption that telepathy exists. Otherwise, according to your statement, the fact that there is no scientific evidence to support the existence of, say, Russell's celestial teapot, or an inivisible pink unicorn, is merely stating that science is not equipped to find it. Of course, one could merely be rational and not assume that it actually exists in the first place. But hey, let's assume everything exists and it is the weakness of science that there is no scientific evidence. So what method of establishing evidence would you prefer to use?